Pine Research Electrode Polishing Guide

1Abstract

Pine Research offers a kit (part number: AKPOLISH) Electrode Polishing Kit containing various polishing materials manufactured by Buehler, Ltd.  This kit contains solutions of finely ground aluminum oxide (alumina) compounds and polishing cloths that can be used to re-polish your electrode after use.  There are as many different opinions about the best way to polish electrodes as there are electrochemists in the world.  The advice provided here comes from experience of our electrochemists, as well as the machinists who make the electrodes at Pine Research.

2Polishing Kit Contents Overview

The electrode polishing kit from Pine Research (part number: AKPOLISH) Electrode Polishing Kit includes the following items: adhesive-backed micropolishing pads, adhesive-backed Nylon polishing pads, 600 grit silicon carbide abrasive paper, and three bottles of alumina slurry suspension (5 μm, 0.3 μm, and 0.05 μm) (see Figure 1).

Figure 1. Contents of the Pine Research Electrode Polishing Kit

3General Polishing and Cleaning Instructions

3.1Routine Cleaning

1. Remove the backing and affix a piece of microfiber polishing cloth to a still flat surface.  Commonly, this is a thicker sheet of glass or polymer, dedicated to electrode polishing.
2. Dispense a small volume of 0.05 μm alumina slurry onto the microcloth.  In general, about 3 mm round spot is sufficient.
3. Polish the electrode against the slurry, keeping the electrode surface parallel to the surface of the cloth.  A figure-8 pattern while gently turning the electrode is a useful technique.
4. Clean the alumina particles off the electrode using distilled water.
5. OPTIONAL: Rinse the electrode surface in an ultrasonication bath (containing distilled water) for a 1-5 minutes to shake loose any alumina particles.  Be sure to suspend only the electrode surface in solution, perhaps by using a ring stand and clamp (i.e., do not place the entire assembly into the ultrasonication bath).

3.2Periodic Cleaning

1. Remove the backing and affix a piece of microcloth polishing cloth to a still flat surface.  Commonly, this is a thicker sheet of glass or polymer, dedicated to electrode polishing.
2. Dispense a small volume of 0.3 μm alumina slurry onto the microcloth.  In general, about 3 mm round spot is sufficient.
3. Polish the electrode against the slurry, keeping the electrode surface parallel to the surface of the cloth.  A figure-8 pattern while gently turning the electrode is a useful technique.
4. Clean the alumina particles off the electrode using distilled water.
5. OPTIONAL: Rinse the electrode surface in an ultrasonication bath (containing distilled water) for a 1-5 minutes to shake loose any alumina particles.  Be sure to suspend only the electrode surface in solution, perhaps by using a ring stand and clamp (i.e., do not place the entire assembly into the ultrasonication bath).
6. Perform a Routine Cleaning with 0.05 μm alumina (as described in Section 3.1).

3.3Aggressive Cleaning

1. Remove the backing and affix a Nylon polishing pad to a stiff flat surface. Commonly, a thicker sheet of glass or polymer, dedicated to electrode polishing, is used solely for electrode polishing.
2. Dispense a small volume of 5 μm alumina slurry onto the Nylon.  In general, about 3 mm round spot is sufficient.
3. Polish the electrode against the slurry, keeping the electrode surface parallel to the surface of the cloth. A figure-8 pattern while gently turning the electrode is a useful technique.
4. Clean the alumina particles off the electrode using distilled water.
5. OPTIONAL: Rinse the electrode surface in an ultrasonication bath (containing distilled water) for a 1-5 minutes to shake loose any alumina particles. Be sure to suspend only the electrode surface in solution, perhaps by using a ring stand and clamp (i.e., do not place the entire assembly into the ultrasonication bath).
6. Perform a Periodic Cleaning with 0.3 μm alumina (as described in Section 3.2).
7. Perform a Routine Cleaning with 0.05 μm alumina (as described in Section 3.1)

3.4Complete Re-polish

1. Remove the backing and affix a piece of 600 grit silicon carbide paper to a stiff flat surface.  Commonly, a thicker sheet of glass or polymer, dedicated to electrode polishing, is used solely for electrode polishing.
2. Add a small volume of deionized water to the pad.  Polish the electrode against the sandpaper, keeping the electrode surface parallel to the surface of the cloth.  A figure-8 pattern while gently turning the electrode is a useful technique.
3. Clean the any particles off the electrode using distilled water.
4. OPTIONAL: Rinse the electrode surface in an ultrasonication bath (containing distilled water) for a 1-5 minutes to shake loose any particles.  Be sure to suspend only the electrode surface in solution, perhaps by using a ring stand and clamp (i.e., do not place the entire assembly into the ultrasonication bath).
5. Perform an Aggressive Cleaning with 5 μm alumina (as described in Section 3.3).
6. Perform a Periodic Cleaning with 0.3 μm alumina (as described in Section 3.2).
7. Perform a Routine Cleaning with 0.05 μm alumina (as described in Section 3.1).

3.5Polishing ChangeDisk Inserts

Figure 2. Place disk insert on clean polishing cloth with the polished face downwards

Figure 3. Gently bring PTFE disk holder down onto the disk insert to install the disk insert into the holder

Figure 4. The disk insert is now ready to be polished in one of the methods described above

Figure 5. Carefully push PTFE holder down until the disk and holder surfaces are flush

Figure 6. Polish the disk against the alumina slurry using a circular or figure-8 motion while pressing down firmly

Figure 7. After polishing, clean disk thoroughly and eject it from the holder using the push rod